Answered

If you buy from a VAT REGISTERED seller they can zero rate your item. I think you can claim back VAT from HMRC but the process will be very slow...everything is! You will also be subject to any import duties, handling fees (from shipper) and Australian VAT which will be based upon the total amount paid plus shipping I expect...like here in UK ......so if it is an expensive item it will make a lot of difference if VAT is added.

your best bet if they are not VAT registered is to contact HMRC first to get advice.